He runs into Conis.

Luffy returned to the palace, going by the infirmary to have his injuries checked out at Kaya's insistence. While she was certain she had done an adequate job treating him, she insisted on him getting a second opinion from the Amazon healers.

Thus, Luffy got into a bed, grumbling slightly about Kaya worrying too much. "Luffy, is that you?" a female voice asked, and he turned to see Conis sitting in a nearby bed, grinning at him.

"Oh, hello Conis!" Luffy grinned, sitting up. "What are you doing here?"

"Well... Remember how you had oxygen deprivation when you first came to Skypiea?" she asked him, and he nodded. "Turns out the condition works in reverse too, I was so used to very little oxygen that when the Amazons brought me down here, I ended up with some oxygen poisoning. I'm just doing a regular check up to be sure my body is adapting properly."

"Ah," Luffy nodded. That made some sense. "Do you know when the healer will be by?"

"Barring any major medical emergencies, the current healer on duty is on a half hour lunch break, she left about three minutes ago..." Conis shrugged.

Luffy smirked a bit at that. Plenty of time for some quick fun...